New insights to how imported wood pellets help support sustainable forest management in the United States

The ongoing debate about costs and benefits of wood-pellet based bioenergy production in the southeastern United States (SE US) requires an understanding of the science and context influencing market decisions associated with its sustainability. Production of pellets has garnered much attention as US exports have grown from negligible amounts in the early 2000s to 4.6 million metric tonnes in 2015. Currently, 98% of these pellet exports are shipped to Europe to displace coal in power plants.

This paper asks, “How is the production of wood pellets in the SE US affecting forest systems and the ecosystem services they provide?”

International report presents status and prospects for renewable energy using wood pellets from the southeastern United States

To address this question, the authors review current forest conditions and the status of the wood products industry, how pellet production affects ecosystem services and biodiversity, and what methods are in place to monitor changes and protect vulnerable systems. Scientific studies provide evidence that wood pellets in the SE US are a fraction of total forestry operations and can be produced while maintaining or improving forest ecosystem services.

Ecosystem services are protected by the requirement to utilize loggers trained to apply scientifically-based best management practices in planning and implementing harvest. Bioenergy markets supplement incomes to private rural landholders and provide an incentive for forest management practices that can simultaneously benefit water quality and wildlife and reduce risk of fire and insect outbreaks. Bioenergy can also increase the value of forest land to landowners, thereby decreasing likelihood of conversion to non-forest uses.  As with all land-use activities, effects on biodiversity and ecosystem services of producing pellets for bioenergy are highly variable and context specific and can have differential effects across the landscape and over time. Negative impacts can be avoided or reduced by identifying priority areas for conservation and adopting management plans tailored to best achieve multiple goals in production forests.

Monitoring and evaluation are essential to verify that regulations and good practices are achieving goals and to enable timely responses if problems arise. Conducting rigorous research to understand how conditions change in response to management choices requires baseline data, monitoring, and appropriate reference scenarios. Long-term monitoring data on forest conditions should be publicly accessible and utilized to inform adaptive management.

“Prospects for renewable energy using wood pellets” was produced through an effort coordinated by the Department of Energy’s Oak Ridge National Laboratory (ORNL) following a Bioenergy Study Tour held in April 2016. During the Study Tour, participants from the US and eight other nations visited an old growth forest as well as managed forests, a biomass conversion facility, and a pellet mill. The Tour was an excellent way to facilitate communication about bioenergy crops in the US, for different places have unique land-use histories, regulations, and ways to implement good management practices.

“This report demonstrates how science-based analysis can help us make progress toward understanding how production of wood-based pellets can enhance ecosystem services of southeastern forest systems,” said lead author Virginia Dale, Director of ORNL’s Center for BioEnergy Sustainability.

Dr Carly Whittaker, from Rothamsted Research (UK) and a Post-Doctoral Researcher working in the Supergen Bioenergy Hub, attended the Study Tour. “It was helpful to observe the truly vast scale of managed forestlands are in the South US and how productive they are. It is important to realise how diverse the forestlands are in terms of local management practices and how different landowners respond differently to changes in markets. Overall, it is obvious that the level of regulation to ensure that biomass is grown and sourced sustainably is extensive and thorough”.

“Meeting climate change mitigation goals is expected to increase biomass use globally. This new industry in the southeast US provides a great opportunity to gather scientific evidence about how forests can be protected and environmental performance improved as demand increases” said Dr Raphael Slade, Senior Research Fellow at Imperial College London.

Caspar Donnison, doctoral student in bioenergy at the University of Southampton (UK) also attended the Study Tour and said: “Visiting key stakeholders in the US forestry industry helped to put bioenergy into the broader context in the Southeast US; biomass for wood pellets only accounted for around 2% of forest harvest removals in the SE US in 2014. It was also important to understand the economics of the forestry industry in the US, with wood pellets typically low value products that are not driving major forest management decisions.”

Joining ORNL in preparing the report were researchers from the Argonne National Laboratory and the National Renewable Energy Laboratory; foresters and land owners from the southeastern United States; and scientists from Australia, Brazil, Canada, Denmark, Germany, Poland, Sweden, The Netherlands, the United Kingdom, and the United States.